1.) Field of the Invention
The present invention pertains to a charge transfer shift register provided with a voltage sensing device using a floating-potential diode.
2.) Description of the Prior Art
According to a well known method in the prior art in the field of charge transfer devices, voltage sensing is done with a diode, the potential of which is pre-charged to a reference value before receiving the signal charge. This method of sensing charges is described, in particular, in the article "Les dispositifs a transfert de charge" (Charge Transfer Devices), published in the Revue Technique THOMSON-CSF, volume 12, number 1, March 1980, pages 41 to 45.
FIG. 1 gives a schematic drawing of a charge transfer shift register seen from above. The figure shows the limits of the transfer channel of the charges 1, which have a constant width, perpendicular to the direction in which the charges are transferred, indicated by a horizontal arrow. The figure also depicts a few rectangular electrodes 2 which are identical to one another. The shift register ends in a diode 3 designed to collect the charges coming from the register. This diode comprises a first part which occupies the entire width of the channel, followed by a second part, of smaller width, to which is connected the input of a high-impedance output amplifier. This known structure can be used to conduct a voltage sensing operation using a floating-potential diode.